CouchDB - More Updates ...

I was lucky to attend a session by my colleague who invested a lot of time in getting a prototype of couchDB to work. Some of my observations...

• Dont map it to features of relational db
• Doesnt enforce user security/isolation levels
• It is document-based database
• Stores JSON format documents
• For better read speeds, we need VIEWS to be pre-created
• Event consistent model
• Follows Brewer's CAP theorem
• Equivalent of WHERE clause is Map-Reduce way of selecting & aggregating contents.
• Definitely not an enterprise class database
• Excellent for applications that can model and consume document databases (eg. LDAP structure, Orkut like sites, user profiles, patient profiles, employee details database etc)

I love to write code in Ruby :-)

BULK UPDATE using FORALL in Oracle PLSQL - Awesome experience..

In one of the projects I work, there arose a need to conditionally update a few column values of a table. How many rows did we need to update ? Roughly 5 million rows out of 252 million total rows.

Experimented many approaches to get this done. Some of them ....

1. Use a single UPDATE statement (Worst thing to ever do for huge data updates)

2. Update in lots of 50K - using plain update statement (Kind of OK, though it handled shorter commits, I wasnt happy with performance)

3. Fantastic result : When I used PLSQL(bulk update using FORALL), I realized I had been under utilizing PLSQL for my day to day jobs. No doubt... Oracle PLSQL rocks.

CouchDB - Are we getting oriented to newer DBs ?

It was inspiring to read about CouchDB - Document based DB. Is it going to mark the end of the RDBMS era ? I have my own questions of how faster a fetch operation could be made on a document based DB.


Or will this confined to specific applications ? Lets wait for CouchDB's user experience feedback.

When is the next post ?

Work has been keeping me very busy ... Recently I was going thru Oracle performance tuning guide. Also found some interesting problems on the job. I am sketching the content. will post soon.

New work laptop

I just started loving the new laptop Dell Latitude E6400. Its looks are awesome !
Will wait for a Mac Book option too. When will the day come ?